TM 11-439 Flash Ranging Set GR-4-A, 1943-11-01 TABLE OF CONTENTS Paragraph Page SECTION I. Description 1 General 1 2 List of component parts 1-3 3 Switchboard BD-70 3-5 4 Power 5 5 Outpost Unit BE-51 7 6 Capacitor Unit BE-59 7 7 Telephone EE-8-(*) 9 8 Protector AR-8 9 9 Miscellaneous parts 9-11 SECTION II. Installation and Operation 10 Installation 11-13 11 Preparation for use 13-14 12 Operation 14-15 SECTION III. Functioning of Parts 13 Switchboard BD-70 15-19 14 Protector AR-8 19 15 Capacitor Unit BE-59 19 16 Outpost Unit BE-51 19 17 Head Set HS-30-(*) 19 SECTION IV. Maintenance 18 Upkeep and Repair 20 SECTION V. Supplementary Data 19 Tabular list of replaceable parts 21-57 20 Spare parts 58 21 Tools 58 22 List of manufacturers 58 LIST OF ILLUSTRATIONS Fig. No. Title Page 1 Switchboard BD-70 (Flash Ranging) VI 2 Flash ranging components, less Switchboard BD-70. 2 3 Switchboard BD-70, rear panel view 4 4 Outpost Unit BE-51, assembled 6 5 Outpost Unit BE-51, wiring diagram 6 6 Capacitor Unit BE-59 7 7 Telephone EE-8-(*) 8 8 Protector Unit AR-8 8 9 Connecting diagram 10 10 Switchboard BD-70, folded for transportation 12 11 Switchboard BD-70, front panel view 16 12 Location of parts for Switchboard BD-70, cabinet 22 13 Location of parts for Switchboard BD-70, front view 24 14 Location of parts for Switchboard BD-70, rear view 26 15 Location of parts for Switchboard BD-70, top rear view. 28 16 Location of parts for Handset TS-9 36 17 Location of parts for Telephone EE-8-(*) 38 18 Location of parts for Cord CD-425 48 19 Location of parts for Protector AR-8 50 20 Location of parts for Outpost Unit BE-51 52 21 Other components 55 22 Battery BB-29 with Strap ST-21 56 23 Switchboard BD-70, schematic diagram 59